Butadiene sequestration via sulfur dioxide charged zeolite beds

ABSTRACT

In an example, a method of butadiene sequestration includes receiving an input stream that includes butadiene. The method includes directing the input stream to a first sulfur dioxide charged zeolite bed for butadiene sequestration via a first chemical reaction of butadiene and sulfur dioxide to form sulfolene.

I. FIELD OF THE DISCLOSURE

The present disclosure relates generally to butadiene sequestration viasulfur dioxide charged zeolite beds.

II. BACKGROUND

Butadiene (1,3-butadiene) is produced during combustion and pyrolysis oforganic compounds and also through steam cracking of petroleum products.Butadiene is widely used in the production of rubber, plastics andcopolymers such as acrylics. Butadiene is indicated to be carcinogenicto humans through inhalation. Approaches to removal of butadiene from agaseous waste stream (such as via distillation) may be challengingand/or expensive.

III. SUMMARY OF THE DISCLOSURE

According to an embodiment, a method of butadiene sequestration includesreceiving an input stream that includes butadiene. The method includesdirecting the input stream to a first sulfur dioxide charged zeolite bedfor butadiene sequestration via a first chemical reaction of butadieneand sulfur dioxide to form sulfolene.

According to another embodiment, a butadiene sequestration systemincludes a first fluid interface to receive an input stream thatincludes butadiene. The butadiene sequestration system further includesa first sulfur dioxide charged zeolite bed to sequester butadiene fromthe input stream via a chemical reaction of butadiene and sulfur dioxideto form sulfolene. The butadiene sequestration system further includes asecond fluid interface to provide and output stream from the firstsulfur dioxide charged zeolite bed.

According to another embodiment, a method of controlling a butadienesequestration process is disclosed. The method includes receiving, at acontrol device, an indication from a butadiene detector that butadienedetected in an output stream exceeds a butadiene threshold. The methodfurther includes sending a first valve positioning signal from thecontrol device to a first valve, the first valve to redirect an inputstream that includes butadiene to a sulfur dioxide charged zeolite bedfor butadiene sequestration via a chemical reaction of the butadiene andsulfur dioxide to form sulfolene.

One advantage of the present disclosure is the ability to sequesterbutadiene from a gaseous waste stream via a chemical reaction ofbutadiene and sulfur dioxide at a sulfur dioxide charged zeolite bed toform sulfolene. Another advantage of the present disclosure is theability to recharge the zeolite bed with recycled sulfur dioxide thatmay be produced from the solid sulfolene that is scrubbed from thezeolite bed.

Features and other benefits that characterize embodiments are set forthin the claims annexed hereto and forming a further part hereof. However,for a better understanding of the embodiments, and of the advantages andobjectives attained through their use, reference should be made to theDrawings and to the accompanying descriptive matter.

IV. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example of a system thatutilizes sulfur dioxide charged zeolite bed(s) to sequester butadienefrom an input stream by chemically reacting butadiene and sulfur dioxideto form sulfolene, according to a particular embodiment;

FIG. 2 is a block diagram illustrating an example of butadienesequestration at a first sulfur dioxide charged zeolite bed via achemical reaction of sulfur dioxide and butadiene to form sulfolene,according to a particular embodiment;

FIG. 3 is a block diagram illustrating an example of butadienesequestration at a second sulfur dioxide charged zeolite bed (e.g.,during recharging of the first zeolite bed of FIG. 2), according to aparticular embodiment;

FIG. 4 is a block diagram illustrating an example of zeolite bedscrubbing to remove sulfolene that is formed as a result of the chemicalreaction of butadiene and sulfur dioxide, according to a particularembodiment;

FIG. 5 is a block diagram illustrating an example of zeolite bedrecharging with sulfur dioxide after zeolite bed scrubbing to remove thesulfolene from the zeolite bed, according to a particular embodiment;

FIG. 6 is a flow diagram illustrating a particular embodiment of amethod of removing butadiene from an input stream by directing the inputstream to a sulfur dioxide charged zeolite bed for butadienesequestration via a chemical reaction of butadiene and sulfur dioxide toform sulfolene;

FIG. 7 is a flow diagram illustrating a particular embodiment of amethod of controlling a process of butadiene sequestration; and

FIG. 8 is a block diagram of an exemplary computer system operable tosupport embodiments of computer-implemented methods, computer programproducts, and system components as illustrated in FIGS. 1-7.

V. DETAILED DESCRIPTION

The present disclosure relates to systems and methods of butadienesequestration using one or more sulfur dioxide charged zeolite beds. Asulfur dioxide charged zeolite bed may be used for butadienesequestration via a chemical reaction of butadiene with sulfur dioxideto form sulfolene. Further, a butadiene detector may be used to monitoran output stream, and when butadiene that is detected in the outputstream exceeds a butadiene threshold, a control device (e.g., aprogrammable logic controller (PLC) device or other computing device)may redirect a butadiene-containing input stream to a second sulfurdioxide charged zeolite bed for butadiene sequestration. While thesecond sulfur dioxide charged zeolite bed is being used for butadienesequestration, the first sulfur dioxide charged zeolite bed may bescrubbed to remove the sulfolene and recharged with sulfur dioxide.After being scrubbed and recharged, the first sulfur dioxide zeolite bedmay be utilized for butadiene sequestration (e.g., after detection ofbutadiene in an output stream of the second sulfur dioxide chargedzeolite bed).

Butadiene (1,3-butadiene) may undergo a cheletropic, [4+1] cycloadditionwith sulfur dioxide to form sulfolene (as shown in the chemical reactiondiagrams illustrated in FIGS. 2 and 3). Sulfolene may be used as aprecursor to industrial solvents or as a safer alternative fortransporting butadiene. Reaction between sulfur dioxide and butadienedoes not require solvents or additional reagents, and the cycloadditionreaction may occur at room temperature (and accelerates at highertemperatures). Such sulfur dioxide reactivity is specific to butadiene,and therefore competitive reactivity with other waste stream materialsmay be unlikely. Furthermore, sulfolene is a relatively inert solid.Accordingly, in-situ generated sulfolene may not be a component of agaseous waste stream. Thus, the present disclosure describes systems andmethods of introducing sulfur dioxide (e.g., via hydrogen bonding of SO₂to pores of a zeolite bed) into a gaseous waste stream in order tosequester butadiene in the form of (solid) sulfolene (e.g., in the poresof the zeolite bed).

Referring to FIG. 1, a block diagram of a particular embodiment of abutadiene sequestration system using sulfur dioxide charged zeolitebed(s) is illustrated and is generally designated 100. In FIG. 1, aninput stream (e.g., a gaseous waste stream) that includes butadiene maybe directed to a sulfur dioxide charged zeolite bed (or multipleSO₂-charged zeolite beds) for butadiene sequestration via a chemicalreaction of butadiene and sulfur dioxide to form sulfolene. Asillustrated and further described herein with respect to FIG. 2, thechemical reaction includes the butadiene undergoing a cheletropic, [4+1]cycloaddition with the sulfur dioxide to form the sulfolene. Asdescribed further herein with respect to FIGS. 3-5, utilizing multiplesulfur dioxide charged zeolite beds allows for sulfolene scrubbing andsulfur dioxide recharging without interrupting a process of sequesteringbutadiene from the input stream.

In the particular embodiment illustrated in FIG. 1, the butadienesequestration system 100 includes a first SO₂-charged zeolite bed 102and a second SO₂-charged zeolite bed 104. In alternative embodiments, analternative number and/or arrangement of SO₂-charged zeolite beds may beutilized for butadiene sequestration. In the example of FIG. 1, abutadiene-containing gas source 106 provides an input stream 108 thatincludes butadiene. It will be appreciated that the SO₂-charged zeolitebeds 102, 104 may be utilized to sequester butadiene from an alternativenumber of butadiene-containing gas sources and/or input streamscontaining butadiene.

The butadiene sequestration system 100 includes a first fluid interface(e.g., a first valve 110) to receive the input stream 108 that includesbutadiene. In the particular embodiment illustrated in FIG. 1, the firstvalve 110 is shown in a first operating position to provide a firstfluid path to the first SO₂-charged zeolite bed 102. As illustrated andfurther described herein with respect to FIG. 2, the first valve 110 maybe configured to provide the first fluid path to the first SO₂-chargedzeolite bed 102 in the first operating position and to provide a secondfluid path (e.g., to the second SO₂-charged zeolite bed 104) in a secondoperating position. As illustrated and further described herein withrespect to FIGS. 3-5, when the first valve 110 is in the secondoperating position, the first SO₂-charged zeolite bed 102 may beisolated from the input stream 108 to allow for removal of sulfolene andrecharging with sulfur dioxide.

The butadiene sequestration system 100 also includes a butadienedetector 112 for inline monitoring of an output stream 114 (or multipleoutput streams) of an SO₂-charged zeolite bed (or multiple SO₂-chargedzeolite beds). The butadiene detector 112 is configured to detect and/orquantify butadiene (e.g., an amount, a concentration, etc.) in theoutput stream 114 (identified as “Butadiene-Scrubbed Output Stream” inFIG. 1). The butadiene sequestration system 100 further includes acontrol device 116 (e.g., a PLC device) that is communicatively coupledto the butadiene detector 112. The control device 116 may be configuredto receive information regarding an amount or concentration of butadienein the output stream 114 for comparison to a butadiene threshold. Thebutadiene threshold may represent a particular amount or concentrationof butadiene that is indicative of saturation or near saturation of thefirst SO₂-charged zeolite bed 102 with sulfolene or another indicationof inadequate sulfur dioxide being available for chemical reaction withbutadiene. The control device 116 may be configured to direct the inputstream 108 to an alternate SO₂-charged zeolite bed for butadienesequestration in response to determining that butadiene detected in theoutput stream 114 of a particular SO₂-charged zeolite bed exceeds thebutadiene threshold. As an example, when the output stream 114corresponds to an output stream of the first SO₂-charged zeolite bed102, the control device 116 may be configured to direct the input stream108 to the second SO₂-charged zeolite bed 104. As another example, whenthe output stream 114 corresponds to an output stream of the second 50₂-charged zeolite bed 104, the control device 114 may be configured todirect the input stream 108 to the first SO₂-charged zeolite bed 104.

In the particular embodiment illustrated in FIG. 1, the butadienesequestration system 110 further includes a sulfolene removal subsystem120, a butadiene collection subsystem 122, and a sulfur dioxidecollection subsystem 124. As illustrated in the chemical reactiondiagram of FIG. 4, in some cases, removal of solid sulfolene from thefirst SO₂-charged zeolite bed 102 may include thermal scrubbing todecompose the sulfolene into butadiene and sulfur dioxide. In this case,butadiene may be separated from the sulfur dioxide and sent to thebutadiene collection subsystem 122, and sulfur dioxide may be sent tothe sulfur dioxide collection subsystem 124. As illustrated and furtherdescribed herein with respect to FIG. 5, the sulfur dioxide collected atthe sulfur dioxide collection subsystem 124 may be recycled for use inrecharging a zeolite bed.

FIG. 1 illustrates that the butadiene sequestration system 100 mayinclude a second fluid interface (e.g., a second valve 130) for removalof the solid sulfolene that is formed in the pores of the firstSO₂-charged zeolite bed 102 (e.g., during zeolite scrubbing 132). Thebutadiene sequestration system 100 may also include a third fluidinterface (e.g., a third valve 134) for providing additional sulfurdioxide to the first SO₂-charged zeolite bed 102 (e.g., during zeoliterecharging 136). In the particular embodiment illustrated in FIG. 1, thesecond valve 130 is shown in a first operating position (e.g., a closedposition when not performing the zeolite scrubbing 132), and the thirdvalve 134 is shown in a first operating position (e.g., a closedposition when not performing the zeolite recharging 136). As illustratedand further described herein with respect to FIG. 4, the second valve130 may be configured to provide a path from the first SO₂-chargedzeolite bed 102 to the sulfolene removal subsystem 120 in a secondoperating position (e.g., an open position for removal of solidsulfolene via thermal/solvent processing). As illustrated and furtherdescribed herein with respect to FIG. 5, the third valve 134 may beconfigured to provide a path from the sulfur dioxide collectionsubsystem 124 to the first SO₂-charged zeolite bed 102 in a secondoperating position (e.g., an open position for recharging with sulfurdioxide).

In operation, the input stream 108 that includes butadiene is directedto the first SO₂-charged zeolite bed 102 via the first valve 110 forbutadiene sequestration (when the first valve 110 is in the firstposition). As illustrated and further described herein with respect toFIG. 2, at least a portion of the butadiene molecules in the inputstream 108 react with sulfur dioxide molecules at a plurality of porelocations of the first SO₂-charged zeolite bed 102. The butadienedetector 112 monitors the (butadiene-scrubbed) output stream 114 forbutadiene. In response to the butadiene detector 112 detecting butadienein the output stream 114 that exceeds a butadiene threshold, the controldevice 116 sends a valve positioning signal to the first valve 110 todirect the input stream 108 to the second SO₂-charged zeolite bed 104for butadiene sequestration (as illustrated and further described hereinwith respect to FIG. 3). As illustrated and further described hereinwith respect to FIGS. 4 and 5, the control device 116 may send valvepositioning signals to the second valve 130 and to the third valve 134in order to provide fluid paths to the first SO₂-charged zeolite bed 102for performing operations associated with the zeolite scrubbing 132 andthe zeolite recharging 136.

When the first valve 110 is in the second position, the input stream 108that includes butadiene is directed to the second SO₂-charged zeolitebed 104 for butadiene sequestration. As illustrated and furtherdescribed herein with respect to FIG. 3, at least a portion of thebutadiene molecules in the input stream 108 react with sulfur dioxidemolecules at a plurality of pore locations of the second SO₂-chargedzeolite bed 104. The butadiene detector 112 monitors the(butadiene-scrubbed) output stream 114 for butadiene. In response to thebutadiene detector 112 detecting butadiene in the output stream 114 thatexceeds a butadiene threshold, the control device 116 sends a valvepositioning signal to the first valve 110 to direct the input stream 108to the first SO₂-charged zeolite bed 102 (or to another SO₂-chargedzeolite bed, not shown in FIG. 1) for butadiene sequestration. WhileFIGS. 1, 4, and 5 illustrate the second valve 130 and the third valve134 providing paths to the first SO₂-charged zeolite bed 102, it will beappreciated that alternative and/or additional valves may be used toprovide fluid paths to the second SO₂-charged zeolite bed 104 (forscrubbing/recharging of the second SO₂-charged zeolite bed 104).

Thus, FIG. 1 illustrates a butadiene sequestration system that directs abutadiene-containing input stream (e.g., a gaseous waste stream) to oneor more SO₂-charged zeolite beds for butadiene sequestration via achemical reaction of butadiene and sulfur dioxide to form sulfolene.FIG. 1 further illustrates that utilizing multiple SO₂-charged zeolitebeds may prevent interruption of the butadiene sequestration process byredirecting the butadiene-containing input stream from a firstSO₂-charged zeolite bed to a second SO₂-charged zeolite bed in order toallow for sulfolene removal and sulfur dioxide recharging at the firstSO₂-charged zeolite bed.

FIG. 2 is a diagram 200 illustrating an example of butadienesequestration at a first sulfur dioxide charged zeolite bed via achemical reaction of sulfur dioxide (that is hydrogen-bonded in azeolite pore) and butadiene to form sulfolene. In FIG. 2, selectedportions of the butadiene sequestration system 100 of FIG. 1 are shownfor illustrative purposes only. In particular, FIG. 2 is designed toillustrate butadiene sequestration via a single SO₂-charged zeolite bed(e.g., the first SO₂-charged zeolite bed 102). FIG. 3 illustratesselected portions of the butadiene sequestration system 100 of FIG. 1related to butadiene sequestration via an alternate SO₂-charged zeolitebed (e.g., the second SO₂-charged zeolite bed 104). FIGS. 4 and 5illustrate selected portions of the butadiene sequestration system 100of FIG. 1 related to scrubbing/recharging of a single SO₂-chargedzeolite bed (e.g., the first SO₂-charged zeolite bed 102).

In the particular embodiment illustrated in FIG. 2, the first valve 110is in a first operating position (identified as “Position (1)” in FIG.2) to provide a first fluid path for the input stream 108 to the firstSO₂-charged zeolite bed 102. FIG. 2 includes a chemical reaction diagramillustrating butadiene (1,3-butadiene) undergoing a cheletropic, [4+1]cycloaddition with sulfur dioxide to form sulfolene at the firstSO₂-charged zeolite bed 102. While FIG. 2 illustrates a single SO₂molecule chemically reacting with a single 1,3 butadiene molecule toform a single sulfolene molecule, it will be appreciated that the firstSO₂-charged zeolite bed 102 includes multiple sulfur dioxide moleculesat multiple zeolite bed pore locations available for chemical reactionwith multiple butadiene molecules. FIG. 2 illustrates a particularexample of reaction conditions (e.g., a temperature in a range of about25° C. to about 100° C.), it will be appreciated that the particularreaction conditions may vary. The chemical reaction of sulfur dioxideand butadiene is an equilibrium reaction, with the equilibrium shiftedtoward sulfolene at temperatures less than about 100° C. As illustratedand further described herein with respect to FIG. 4, the equilibrium maybe shifted toward sulfur dioxide and butadiene at temperatures greaterthan about 100° C. (e.g., greater than about 120° C.).

In FIG. 2, the (butadiene-scrubbed) output stream 114 corresponds to anoutput stream from the first SO₂-charged zeolite bed 102. In this case,the butadiene detector 112 monitors the output stream 114 for butadieneto determine whether detected butadiene exceeds a threshold that mayindicate that inadequate sulfur dioxide is available at the firstSO₂-charged zeolite bed 102 for reaction with butadiene in the inputstream 108. As further described herein with respect to FIG. 3, when thedetected butadiene exceeds the butadiene threshold, the control device116 may send a valve positioning signal to the first valve 110 toredirect the input stream 108 to another SO₂-charged zeolite bed (e.g.,the second SO₂-charged zeolite bed 104) for butadiene sequestration.Alternatively (e.g., in cases where alternative SO₂-charged beds may notbe available for butadiene sequestration), the control device 116 maysend a valve positioning signal to close the first valve 110 (e.g., toallow for sulfur dioxide recharging).

Thus, FIG. 2 illustrates an example of butadiene sequestration at asulfur dioxide charged zeolite bed via a chemical reaction of butadieneincluded in an input stream (e.g., a gaseous waste stream) and sulfurdioxide to form sulfolene. FIG. 2 further illustrates that inlinemonitoring of an output stream of the sulfur dioxide charged zeolite bedfor butadiene may prevent interruption of the butadiene sequestrationprocess. When butadiene detected in the output stream exceeds abutadiene threshold, the input stream may be directed to an alternatesulfur dioxide charged zeolite bed, as illustrated and further describedherein with respect to FIG. 3.

FIG. 3 is a diagram 300 illustrating an example of butadienesequestration at a second sulfur dioxide charged zeolite bed (e.g.,during scrubbing/recharging of the zeolite bed of FIG. 2). In FIG. 3,selected portions of the butadiene sequestration system 100 of FIG. 1are shown for illustrative purposes only. In particular, FIG. 3illustrates butadiene sequestration via an alternate SO₂-charged zeolitebed (e.g., the second SO₂-charged zeolite bed 104).

In the particular embodiment illustrated in FIG. 3, the first valve 110is in a second operating position (identified as “Position (2)” in FIG.3) to provide a second fluid path for the input stream 108 to the secondSO₂-charged zeolite bed 104 for butadiene sequestration via a chemicalreaction of sulfur dioxide and butadiene to form sulfolene. FIG. 3illustrates that the control device 116 may send a valve positioningsignal 302 to the first valve 110, and the first valve 110 may changefrom the first operating position (as shown in FIG. 2) to the secondoperating position to direct the input stream 108 to the secondSO₂-charged zeolite bed 104. For example, the control device 116 maysend the valve positioning signal 302 to the first valve 110 in responseto determining that butadiene detected in the output stream 114 of thefirst SO₂-charged zeolite bed 102 (shown in FIG. 2) exceeds thebutadiene threshold.

In FIG. 3, after the first valve 110 is switched to the second operatingposition to direct the input stream 108 to the second SO₂-chargedzeolite bed 104, the (butadiene-scrubbed) output stream 114 correspondsto an output stream from the second SO₂-charged zeolite bed 104. In thiscase, the butadiene detector 112 monitors the output stream 114 forbutadiene to determine whether detected butadiene exceeds a thresholdthat may indicate that inadequate sulfur dioxide is available at thesecond SO₂-charged zeolite bed 104 for reaction with butadiene in theinput stream 108. While not shown in FIG. 3, when the detected butadieneexceeds the butadiene threshold, the control device 116 may send asecond valve positioning signal to the first valve 110 to direct theinput stream 108 to another SO₂-charged zeolite bed (e.g., the firstSO₂-charged zeolite bed 102) for butadiene sequestration. For example,the input stream 108 may be directed to the first SO₂-charged zeolitebed 102 after scrubbing/recharging of the first SO₂-charged zeolite bed102, as described further herein with respect to FIGS. 4 and 5.

Thus, FIG. 3 illustrates an example of butadiene sequestration at analternate sulfur dioxide charged zeolite bed via a chemical reaction ofbutadiene and sulfur dioxide to form sulfolene. As illustrated andfurther described herein with respect to FIGS. 4 and 5, the alternatesulfur dioxide charged zeolite bed may allow butadiene sequestration tocontinue during sulfolene scrubbing and sulfur dioxide recharging ofanother (offline) zeolite bed.

FIG. 4 is a diagram 400 illustrating an example of zeolite bed scrubbingto remove sulfolene that is formed as a result of the chemical reactionof butadiene and sulfur dioxide. In FIG. 4, selected portions of thebutadiene sequestration system 100 of FIG. 1 are shown for illustrativepurposes only. In particular, FIG. 4 is designed to illustrate scrubbingof a single zeolite bed (e.g., the first SO₂-charged zeolite bed 102) toremove solid sulfolene that is formed as a result of the chemicalreaction of sulfur dioxide and butadiene.

In the particular embodiment illustrated in FIG. 4, the first valve 110is in the second operating position to direct the input stream 108 tothe second SO₂-charged zeolite bed 104 (not shown in FIG. 4) forbutadiene sequestration. FIG. 4 illustrates that the control device 116may send a valve positioning signal 402 to the second valve 130 to opena second (fluid) path to allow for removal of sulfolene from the firstSO₂-charged zeolite bed 102. For example, the control device 116 maysend the valve positioning signal 402 to the second valve 130 aftersending the valve positioning signal 302 to the first valve 110 (asshown in FIG. 3). Thus, the second SO₂-charged zeolite bed 104 may beused for butadiene sequestration while the first SO₂-charged zeolite bed102 is isolated in order to allow a first set of operations associatedwith sulfolene removal to be performed.

In some cases, the first set of operations associated with sulfoleneremoval includes utilizing one or more solvents to remove the sulfolenefrom the first SO₂-charged zeolite bed 102. In other cases, the firstset of operations may include thermal processing to remove the sulfolenefrom the first SO₂-charged zeolite bed 102. FIG. 4 includes a chemicalreaction diagram of a second chemical reaction to form sulfur dioxideand butadiene from the sulfolene. As previously described with respectto FIG. 2, the chemical reaction of sulfur dioxide and butadiene is anequilibrium reaction, with the equilibrium shifted toward sulfolene attemperatures less than about 100° C. FIG. 4 illustrates that theequilibrium may be shifted toward sulfur dioxide and butadiene attemperatures greater than about 100° C. (e.g., greater than about 120°C.).

In the example of FIG. 4, the thermal processing is illustrated at thesulfolene removal subsystem 120. In some cases, one or more solvents maybe used to remove the solid sulfolene from the first SO₂-charged zeolitebed 102. In other cases, sulfolene removal from the first SO₂-chargedzeolite bed 102 may include direct application of heat to the firstSO₂-charged zeolite bed 102 (e.g., heating to a temperature that isgreater than about 120° C.) to decompose the solid sulfolene intogaseous sulfur dioxide and butadiene. In this example, the gaseoussulfur dioxide and butadiene may flow through the second valve 130, andthe sulfolene removal subsystem 120 may have a reduced temperature(e.g., less than about 100° C.) where the gaseous sulfur dioxide andbutadiene may undergo a second cycloaddition reaction to form solidsulfolene for collection and/or processing.

In the particular embodiment illustrated in FIG. 4, the gaseous sulfurdioxide and butadiene that are formed as a result of the thermalprocessing of sulfolene may be separated (e.g., via distillation orother separation methods, at the sulfolene removal subsystem 120), withthe SO₂ sent to the SO₂ collection subsystem 124 and the butadiene sentto the butadiene collection subsystem 122. As further described hereinwith respect to FIG. 5, the sulfur dioxide that is sent to the SO₂collection subsystem 124 may be utilized for zeolite bed recharging.

Thus, FIG. 4 illustrates an example of sulfolene scrubbing/removal froma zeolite bed in order to allow the zeolite bed to be recharged withsulfur dioxide for subsequent butadiene sequestration. FIG. 4 furtherillustrates that thermal processing of sulfolene may allow sulfurdioxide to be recycled during zeolite bed recharging, as illustrated andfurther described herein with respect to FIG. 5.

FIG. 5 is a diagram 500 illustrating an example of zeolite bedrecharging with sulfur dioxide after zeolite bed scrubbing to remove thesulfolene from the zeolite bed. In FIG. 5, selected portions of thebutadiene sequestration system 100 of FIG. 1 are shown for illustrativepurposes only. In particular, FIG. 5 illustrates recharging of a singlezeolite bed (e.g., the first SO₂-charged zeolite bed 102) with sulfurdioxide after removal of sulfolene (as described herein with respect toFIG. 4). In the particular embodiment illustrated in FIG. 5, at least aportion of the sulfur dioxide that is utilized for zeolite recharging isformed via thermal processing of the sulfolene that is scrubbed from thezeolite bed.

In the particular embodiment illustrated in FIG. 5, the first valve 110is in the second operating position to direct the input stream 108 tothe second SO₂-charged zeolite bed 104 (not shown in FIG. 5) forbutadiene sequestration. FIG. 5 illustrates that the control device 116may second a (second) valve positioning signal 502 to the second valve130 to close the second fluid path to the first SO₂-charged zeolite bed102. For example, the control device 116 may send the (second) valvepositioning signal 502 to the second valve 130 after performingsulfolene removal operation(s), as described herein with respect to FIG.4. Responsive to the (second) valve positioning signal 502, the secondvalve 130 may change from the second operating position (as shown inFIG. 4) to the first operating position (as shown in FIG. 5).

FIG. 5 further illustrates that the control device 116 may send a valvepositioning signal 504 to the third valve 134, and the third valve 134may change from the first operating position (as shown in FIG. 4) to asecond operating position to allow for the zeolite recharging 136 withsulfur dioxide. For example, the control device 116 may send the valvepositioning signal 504 to the third valve 134 after sending the (second)valve positioning signal 502 to the second valve 130. Thus, the firstSO₂-charged zeolite bed 102 may be isolated from the sulfolene removalsubsystem 120 (as shown in FIG. 4) in order to allow a second set ofoperations associated with zeolite recharging to be performed. WhileFIG. 5 illustrates a particular example in which sulfur dioxide that isformed from decomposition of sulfolene (as shown in FIG. 4) is recycledduring the zeolite recharging 136, in other cases the sulfur dioxidethat is used for the zeolite recharging 136 may represent “additional”sulfur dioxide that may be received from an alternative source.

While not shown in FIG. 5, after performing the second set of operationsassociated with the zeolite recharging 136, the control device 116 maysend one or more additional valve positioning signals. As an example,the control device 116 may send an additional valve positioning signalto the third valve 134. Responsive to the additional valve positioningsignal, the third valve 134 may change from the second operatingposition (as shown in FIG. 5) to the first operating position (as shownin FIG. 1). As another example, the control device 116 may send anadditional valve positioning signal to the first valve 110. Responsiveto the additional valve positioning signal, the first valve 110 maychange from the second operating position (as shown in FIG. 5) to thefirst operating position (as shown in FIG. 1) in order to allow forbutadiene sequestration at the first SO₂-charged zeolite bed 102.Alternatively, as described herein with respect to FIG. 3, the controldevice 116 may send the additional valve positioning signal to the firstvalve 110 after butadiene detected in the output stream 114 of thesecond SO₂-charged zeolite bed 104 exceeds the butadiene threshold. Thesecond SO₂-charged zeolite bed 104 may then be scrubbed/recharged in amanner similar to that described above with respect to the firstSO₂-charged zeolite bed 102.

Thus, FIG. 5 illustrates that, after removal of sulfolene that is formedas a result of a chemical reaction of sulfur dioxide and butadiene, azeolite bed may be recharged with sulfur dioxide in order to allow thezeolite bed to be used for butadiene sequestration. In the example ofFIG. 5, the sulfur dioxide that is used to recharge the zeolite bed isformed from thermal decomposition of the sulfolene that is removed fromthe zeolite bed. Alternatively, the zeolite bed may be recharged withsulfur dioxide from another source.

FIG. 6 is a flow diagram that illustrates a particular embodiment of amethod 600 of butadiene sequestration. In FIG. 6, an input stream (thatincludes butadiene) may be directed to a particular sulfur dioxidecharged zeolite bed for butadiene sequestration via a chemical reactionof butadiene and sulfur dioxide to form sulfolene. FIG. 6 illustratesthat butadiene may be monitored in an output stream (e.g., of a firstsulfur dioxide charged zeolite bed). When butadiene detected in theoutput stream exceeds a butadiene threshold, a butadiene-containinginput stream may be directed to another sulfur dioxide charged zeolitebed for butadiene sequestration.

The method 600 includes receiving a butadiene-containing input stream(e.g., a gaseous waste stream that includes butadiene), at 602. Forexample, referring to FIGS. 1 and 2, the input stream 108 that includesbutadiene is received from the butadiene-containing gas source 106. Insome cases, the input stream 108 may represent a gaseous waste stream.To illustrate, the butadiene may be produced during combustion orpyrolysis of organic compounds and/or through steam cracking ofpetroleum products.

The method 600 includes directing the butadiene-containing input streamto a first SO₂-charged zeolite bed for butadiene sequestration, at 604.Butadiene may be sequestered at the first SO₂-charged zeolite bed via achemical reaction (e.g., a cycloaddition reaction) of butadiene andsulfur dioxide to form sulfolene. For example, referring to FIGS. 1 and2, the input stream 108 that includes butadiene may be directed to thefirst SO₂-charged zeolite bed 102 for butadiene sequestration when thefirst valve 110 is in the first operating position. FIG. 2 furtherillustrates that butadiene may be sequestered (as solid sulfolene) atthe first SO₂-charged zeolite bed 102 via a chemical reaction (e.g., a[4+1] cycloaddition reaction) of butadiene and sulfur dioxide to formsulfolene.

The method 600 includes monitoring butadiene in an output stream of thefirst SO₂-charged zeolite bed, at 606. For example, referring to FIGS. 1and 2, the butadiene detector 112 may monitor butadiene in the outputstream 114 of the first SO₂-charged zeolite bed 102.

The method 600 includes determining whether butadiene detected in theoutput stream of the first sulfur dioxide charged zeolite bed exceeds abutadiene threshold, at 608. For example, referring to FIGS. 1 and 2,the control device 116 may receive an indication from the butadienedetector 112 that butadiene detected in the output stream 114 exceeds abutadiene threshold. Butadiene exceeding the butadiene threshold may beindicative of inadequate sulfur dioxide being available at the firstSO₂-charged zeolite bed 102 for chemical reaction with butadiene to formsulfolene.

When the butadiene threshold is not exceeded, the method 600 may returnto 606, and butadiene may continue to be monitored in the output streamof the first sulfur dioxide charged zeolite bed. For example, referringto FIGS. 1 and 2, the butadiene detector 112 may continue to monitor theoutput stream 114 of the first SO₂-charged zeolite bed 102.

When the butadiene threshold is exceeded, the method 600 includesdirecting the butadiene-containing input stream to a second sulfurdioxide charged zeolite bed for butadiene sequestration, at 610.Butadiene may be sequestered at the second sulfur dioxide chargedzeolite bed via a chemical reaction (e.g., a cycloaddition reaction) ofbutadiene and sulfur dioxide to form sulfolene. For example, referringto FIG. 3, the input stream 108 may be directed to the secondSO₂-charged zeolite bed 104 when butadiene detected in the output stream114 (of the first SO₂-charged zeolite bed 102 of FIGS. 1 and 2) exceedsthe butadiene threshold. FIG. 3 further illustrates that the controldevice 116 may send the valve positioning signal 302 to the first valve110 to change to the second operating position in order to provide afluid path to the second SO₂-charged zeolite bed 104.

Thus, FIG. 6 illustrates that an input stream (that includes butadiene)may be directed to a particular SO₂-charged zeolite bed for butadienesequestration via a chemical reaction of butadiene and sulfur dioxide toform sulfolene. An output stream of a SO₂-charged zeolite bed may bemonitored for butadiene. When butadiene detected in the output streamexceeds a butadiene threshold that may be indicative of inadequatesulfur dioxide for reaction with butadiene, the input stream may beredirected to another SO₂-charged zeolite bed for butadienesequestration. By monitoring butadiene in an output stream of a firstSO₂-charged zeolite bed and selectively redirecting an input stream to asecond SO₂-charged zeolite bed, the butadiene sequestration process maycontinue while the first zeolite bed is scrubbed and recharged.

FIG. 7 is a flow diagram that illustrates a particular embodiment of amethod 700 of controlling a process of butadiene sequestration. In FIG.7, a control device (e.g., a PLC device) may be utilized to send valvepositioning signal(s) to direct an input stream that includes butadieneto a sulfur dioxide charged zeolite bed in response to butadienedetected in an output stream exceeding a butadiene threshold. FIG. 7further illustrates that the control device may be utilized to sendvalve positioning signal(s) to allow for sulfolene removal from azeolite bed and for sulfur dioxide recharging of the zeolite bed.

The method 700 includes receiving an indication from a butadienedetector that butadiene detected in an output stream exceeds a butadienethreshold, at 702. For example, referring to FIG. 3, the control device116 may receive an indication from the butadiene detector 112 thatbutadiene detected in the output stream 114 (of the first SO₂-chargedzeolite bed 102 shown in FIG. 2) exceeds a butadiene threshold.

The method 700 includes sending a first valve positioning signal to afirst valve to direct a butadiene-containing input stream to aSO₂-charged zeolite bed for butadiene sequestration, at 704. Butadienemay be sequestered from the input stream via a chemical reaction (e.g.,a cycloaddition reaction) of butadiene and sulfur dioxide to formsulfolene. For example, referring to FIG. 3, the control device 116 maysend the valve positioning signal 302 to the first valve 110 to directthe input stream 108 that includes butadiene to the second SO₂-chargedzeolite bed 104 for butadiene sequestration. FIG. 3 further illustratesthat butadiene may be sequestered from the input stream 108 at thesecond SO₂-charged zeolite bed 104 via a chemical reaction of sulfurdioxide and butadiene to form (solid) sulfolene (e.g., at pore locationsof the second SO₂-charged zeolite bed 104 that includes sulfur dioxidemolecules that are hydrogen bonded to the zeolite bed).

The method 700 includes sending a second valve positioning signal to asecond valve for removal of sulfolene from the zeolite bed (e.g., viathermal/solvent processing), at 706. For example, referring to FIG. 4,the control device 116 may send the valve positioning signal 402 to thesecond valve 130. Responsive to receiving the valve positioning signal402, the second valve 130 may change to the second operating position toprovide a (fluid) path for removal of sulfolene from the firstSO₂-charged zeolite bed 102.

The method 700 includes sending a third valve positioning signal to athird valve for recharging the zeolite bed with sulfur dioxide, at 708.For example, referring to FIG. 5, after sending the (second) valvepositioning signal 502 to the second valve 130, the control device 116may send the valve positioning signal 504 to the third valve 134.Responsive to receiving the valve positioning signal 504, the thirdvalve 134 may change to the second operating position to provide a fluidpath for sulfur dioxide recharging.

Thus, FIG. 7 illustrates that a control device (e.g., a PLC device) maybe used to control a butadiene sequestration process. For example, thecontrol device may send valve positioning signals to different valves inorder to prevent disruption of a butadiene sequestration process as aresult of an inadequate supply of sulfur dioxide for reaction withbutadiene at an SO₂-charged zeolite bed. FIG. 7 further illustrates thatthe control device may be used to send valve positioning signals todifferent valves in order to allow for sulfolene removal from a zeolitebed and for sulfur dioxide recharging of the zeolite bed (e.g., while analternate SO₂-charged zeolite bed is being used for butadienesequestration).

Referring to FIG. 8, an exemplary automated computing machineryincluding a computer 810 is shown. The computer 810 is an exemplaryimplementation of the control device 116 illustrated and furtherdescribed herein with respect to FIGS. 1-5. The computer 810 includes atleast one computer processor (CPU) 812 as well as main memory 814, amemory controller 816, and a non-volatile memory 818. The main memory814 is connected through a memory bus 820 to the memory controller 816.The memory controller 820 and the non-volatile memory 814 are connectedthrough a memory bus 822 and a bus adapter 824 to the processor 812through a processor bus 826.

Stored at the memory 814 is an application 830 that may be a module ofuser-level computer program instructions for carrying out particulartasks (e.g., the operations described with respect to controlling abutadiene sequestration process that utilizes a plurality of sulfurdioxide charged zeolite beds for butadiene sequestration). Also storedat the main memory 814 is an operating system 832. Operating systemsinclude, but are not limited to, UNIX® (a registered trademark of TheOpen Group), Linux® (a registered trademark of Linus Torvalds), Windows®(a registered trademark of Microsoft Corporation, Redmond, Wash., UnitedStates), AIX® (a registered trademark of International Business Machines(IBM) Corp., Armonk, N.Y., United States) i5/OS® (a registered trademarkof IBM Corp.), and others as will occur to those of skill in the art.The operating system 832 and the application 830 in the example of FIG.8 are shown in the main memory 814, but components of the aforementionedsoftware may also, or in addition, be stored at non-volatile memory(e.g., on data storage, such as illustrative data storage 840 and/or thenon-volatile memory 818).

The computer 810 includes a disk drive adapter 842 coupled through anexpansion bus 844 and the bus adapter 824 to the processor 812 and othercomponents of the computer 810. The disk drive adapter 842 connectsnon-volatile data storage to the computer 810 in the form of the datastorage 840 and may be implemented, for example, using Integrated DriveElectronics (“IDE”) adapters, Small Computer System Interface (“SCSI”)adapters, Serial Attached SCSI (“SAS”) adapters, and others as willoccur to those of skill in the art. Non-volatile computer memory alsomay be implemented as an optical disk drive, electrically erasableprogrammable read-only memory (so-called “EEPROM” or “Flash” memory),RAM drives, and other devices, as will occur to those of skill in theart.

The computer 810 also includes one or more input/output (“I/O”) adapters846 that implement user-oriented input/output through, for example,software drivers and computer hardware for controlling input and outputto and from user input devices 848, such as keyboards and mice. Inaddition, the computer 810 includes a communications adapter 850 fordata communications with a data communications network 852. In aparticular embodiment, the communications adapter 852 may be utilized bythe control device 116 of FIGS. 1-5 to communicate with the butadienedetector 112, the first valve 110, the second valve 130, or the thirdvalve 134 to control a butadiene sequestration process. In some cases,the communications adapter 852 may be utilized by the control device 116of FIGS. 1-5 to communicate with the sulfolene removal subsystem 120,the butadiene collection subsystem 122, the sulfur dioxide collectionsubsystem 124, or a combination thereof.

The data communications may be carried out serially through RecommendedStandard 232 (RS-232) connections (sometimes referred to as “serial”connections), through external buses such as a Universal Serial Bus(“USB”), through data communications networks such as internet protocol(IP) data communications networks, and in other ways as will occur tothose of skill in the art. The communications adapter 850 implements thehardware level of data communications through which one computer sendsdata communications to another computer, directly or through a datacommunications network. Examples of the communications adapter 850suitable to use in the computer 810 include, but are not limited to,modems for wired dial-up communications, Ethernet (Institute ofElectrical and Electronics Engineers (IEEE) 802.3) adapters for wirednetwork communications, and IEEE 802.11 adapters for wireless networkcommunications. The computer 810 also includes a display adapter 854that facilitates data communication between the bus adapter 824 and adisplay device 856, enabling the application 830 to visually presentoutput on the display device 856.

Particular embodiments described herein may take the form of an entirelyhardware embodiment, an entirely software embodiment, or an embodimentcontaining both hardware and software elements. In a particularembodiment, the disclosed methods are implemented in software that isembedded in processor readable storage medium and executed by aprocessor that includes but is not limited to firmware, residentsoftware, microcode, etc.

Further, embodiments of the present disclosure, may take the form of acomputer program product accessible from a computer-usable orcomputer-readable storage medium providing program code for use by or inconnection with a computer or any instruction execution system. For thepurposes of this description, a computer-usable or computer-readablestorage medium can be any apparatus that can tangibly embody a computerprogram and that can contain, store, communicate, propagate, ortransport the program for use by or in connection with the instructionexecution system, apparatus, or device.

In various embodiments, the medium can include an electronic, magnetic,optical, electromagnetic, infrared, or semiconductor system (orapparatus or device) or a propagation medium. Examples of acomputer-readable storage medium include a semiconductor or solid statememory, magnetic tape, a removable computer diskette, a random accessmemory (RAM), a read-only memory (ROM), a rigid magnetic disk and anoptical disk. Current examples of optical disks include compactdisk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) anddigital versatile disk (DVD).

A data processing system suitable for storing and/or executing programcode may include at least one processor coupled directly or indirectlyto memory elements through a system bus. The memory elements can includelocal memory employed during actual execution of the program code, bulkstorage, and cache memories that may provide temporary or more permanentstorage of at least some program code in order to reduce the number oftimes code must be retrieved from bulk storage during execution.

Input/output or I/O devices (including but not limited to keyboards,displays, pointing devices, etc.) can be coupled to the data processingsystem either directly or through intervening I/O controllers. Networkadapters may also be coupled to the data processing system to enable thedata processing system to become coupled to other data processingsystems or remote printers or storage devices through interveningprivate or public networks. Modems, cable modems, and Ethernet cards arejust a few of the currently available types of network adapters.

The previous description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the disclosedembodiments. Various modifications to these embodiments will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other embodiments without departing from thescope of the disclosure. Thus, the present disclosure is not intended tobe limited to the embodiments shown herein but is to be accorded thewidest scope possible consistent with the principles and features asdefined by the following claims.

The invention claimed is:
 1. A butadiene sequestration systemcomprising: a first fluid interface to receive an input stream thatincludes butadiene; a first sulfur dioxide charged zeolite bed tosequester butadiene from the input stream via a chemical reaction ofbutadiene and sulfur dioxide to form sulfolene; and a second fluidinterface to provide an output stream from the first sulfur dioxidecharged zeolite bed.
 2. The butadiene sequestration system of claim 1,further comprising a second sulfur dioxide charged zeolite bed tosequester butadiene from the input stream via a chemical reaction of thebutadiene and sulfur dioxide to form sulfolene.
 3. The butadienesequestration system of claim 2, further comprising: a butadienedetector to monitor butadiene in the output stream; a control devicecommunicatively coupled to the butadiene detector, wherein the controldevice is configured to send a valve positioning signal to a valveresponsive to a determination that butadiene detected in the outputstream exceeds a butadiene threshold, and wherein the valve isconfigured to direct the input stream to the second sulfur dioxidecharged zeolite bed for butadiene sequestration responsive to receivingthe valve positioning signal.
 4. The butadiene sequestration system ofclaim 3, wherein the control device includes a programmable logiccontroller (PLC) device, and wherein the valve positioning signalincludes instructions to close a first fluid path to the first sulfurdioxide charged zeolite bed and to open a second fluid path to thesecond sulfur dioxide charged zeolite bed.
 5. The butadienesequestration system of claim 1, further comprising: a second fluidinterface for removal of the sulfolene from the first sulfur dioxidecharged zeolite bed; and a third fluid interface for providingadditional sulfur dioxide to the first sulfur dioxide charged zeolitebed for butadiene sequestration.